I'm not sure if this is what you are going for, but certainly there were pockets of Unionism in the South, and sympathy for the Confederacy in the North, but they did not follow a strict urban/rural divide in the way we might expect based on the politics of 2022 where this divide is stark and predictive from a political science standpoint. Things weren't quite as clean in the 1860s, and what we might expect in terms of allegiance and sympathy doesn't always conform to our expectations; some of the most "rural" parts of the South had some of the strongest Union sympathies, and some of the largest Northern cities were hotbeds of Confederate sympathy. Though in both cases, these are complex issues, and we should neither discount nor overestimate the degree or strength of Unionism in the South.

I will try to give a brief overview. As the secession crisis broke out, seven states would initially decide to secede prior to Lincoln's inauguration, while four other states (Virginia, North Carolina, Arkansas, and Tennessee) would reject secession only to revisit the issue and go with the Deep South after Fort Sumter. The remaining border states where slavery was legal (Missouri, Kentucky, Maryland, and Delaware) all had strong secessionist minorities (with the exception of Delaware) that Lincoln and northern Unionists had to deal with carefully.

Among the Confederate States, the "fire eaters" who most readily embraced secession were almost uniformly from the highest slaveholding regions: the coastal counties of the Carolinas and Georgia, the Mississippi valley, the cotton belt, etc. Voters in the "up country" near Appalachia, where slaveholding was less prevalent, tended to be the least enthusiastic for secession, though many were "cooperationists" who favored a "wait and see" approach rather than denying the legality of secession altogether. An "Appalachian triangle" running from northern Georgia, western North Carolina, and eastern Tennessee (where Andrew Johnson hailed from) tended to be pockets of Unionism or only tepid support for secession, in part because smallholding white farmers from these regions tended to be resentful of the power and influence of big slaveholders, who they rightly knew would gain further influence in the new Confederacy. And more notable still were the largely rural hilly and mountainous counties of western Virginia which broke away and formed a rump government, eventually being recognized as West Virginia. That is probably the single strongest example of outright Unionism in the South, at least at the war's outset. It should be noted, though, that even Southerners who favored the Union often believed this allegiance to be conditional, and "cooperationists" like John Bell who had recently been the candidate of the Constitutional Union Party tended to blame Lincoln rather than the fire-eaters for the outbreak of hostilities (Bell himself would become a supporter of the Confederacy after Tennessee's secession). Other Southerners, though, made individual choices to support the Union, including the aforementioned Andrew Johnson, Texans like Sam Houston (who was deposed as governor for his opposition to secession), and Virginians like George H. Thomas, who rose to the rank of general in the Union Army.

Meanwhile, in the North, there are a couple distinct strains of pro-Confederate sympathy. One, probably the most serious pro-Confederate group of "Copperheads" who were consistently anti-Lincoln, had a strong base of support in the southern counties of states like Ohio, near the Ohio River (and hence having more commercial connections with the South and Mississippi valley). Two of the most prominent Copperheads, Clement Vallandigham and George Pendleton, were both from Ohio. Another group organized in cities, especially those where business depended on trade with Southern states or access to Southern cotton (but certainly not uniformly, as New England had a large concentration of cotton mills but was probably the most stalwart pro-Union and anti-slavery region in the country). Baltimore was a hotbed of secessionist sentiment in 1861, and Maryland as a whole might only have been saved from secession by virtue of the Unionist governor failing to call the largely pro-Southern legislature into action (Maryland had voted for Breckinridge, the fire-eater candidate, in the election of 1860). Riots broke out in response to the entry of Union troops, and secessionists sabotaged rail and communication networks around Baltimore with the tacit approval of the mayor and even Governor Hicks, temporarily cutting Washington off from the rest of the North. This fierce pro-Confederate activity is what spurred Lincoln into suspending habeas corpus in parts of the State, and jailing suspected secessionist politicians. The situation was almost as dire in New York, where investors feared a secession-driven panic on Wall Street, and some financiers wanted Lincoln to compromise to prevent a war--and worse, a dwindling supply of cotton. The mayor, Fernando Wood, openly spoke of New York City issuing its own declaration of secession as a "free city." Wood, however, was unable to sway the Democratic machine in New York, and plenty of other investors figured out ways to profit mightily from the Union war industry, so this talk did not go as far. New York did figure prominently in the worst non-combat violence in the war though (at least in the North), when an anti-draft riot that grew into a racial pogrom against Black New Yorkers, broke out in 1863 (Wood was no longer mayor at that point, but did get elected to the House of Representatives--film fans may remember his character, portrayed by Lee Pace, in Lincoln). The draft riots are a complex bit of history in their own right, so I won't say more here, but that was in part an outgrowth of only lukewarm support for the Union, especially in heavily Democratic wards.

Principal source here is James McPherson's Battle Cry of Freedom, but there are a few other articles I have in my office I can grab when I get back there for further reading.